CL-BibTeX is a compatible replacement for the BibTeX program, written in CL.
BibTeX formats scientific bibliographies for LaTeX according to a style file (.bst).

A BibTeX style file is in fact a program in a simple Forth-Like Language. Only few people can read and customize BibTeX style files, and debugging them is very painful.

CL-BibTeX allows to write BibTeX styles as Common Lisp programs instead.
It also contains an interpreter for the .bst language, so that existing BibTeX styles can still be used.
CL-BibTeX also provides a compiler that produces Common Lisp programs from .bst programs.